Vulcanizing-pad



, J. N. DIESER.

VULCANIZING PAD;

APPLICATION FILED I/IAII. 3o. 1920.

jbl/Em? distribute pressure equally upon the surface UNiTen sraras earner carica,

J'ULIUS N. DIESER, 0F SAN FRANCSCO, CALIFORNIA, ASSGNOR OF ONE-HALF TO ALBERT L. SILVER/STEIN,

OF SAN FRANCISCO, CALIFORNIA.

VULCANIFZINGr-PAD.

' To all w/iom may concer/nf.'

Be it known that I, JULiUs N. DIESER, a

Vcitizen of the United States, residin in the is filled with a granular filling adapted to of an object to be vulcanized.

The objectsof my invention are;

First, to provide a vulcanizing pad adapted to readily conform to the contour of the object to be vulcanized.4 y

Second, to provide a vulcanizing pad ofvdurable character adapted to withstand con-- stant usage. y

Third, to provide a pad of 'substantially the same character of 'material as that which is to be vulcanized,

Fourth, to .provide a vulcanizing pad adapted to receive pressure evenly from 'a clamping means and impart said pressure 1 .equally against all points of the surface to be vulcanized.

I accomplish these and4 other objects by means of the device disclosed in the drawings forming apart of the present specification wherein like charactersof reference are used toA designate similarl parts throughout said Aspecification and drawings, and in which- Figure 1V is a broken side elevation of a vulcanizing mold for retreading automobile tires, portions being broken away`- and shown in section to disclose the application of my improved vulcanizing pad as adapted thereto.

Fig. 2 is a sectional 'view taken along the line2-2 of Fig. l.

. Fig. 3 is a broken side elevation of my vulcanizing pad, portions being shown iii section to disclose the construction thereof. vln repairingr and retreading automobile tires and the like, the practice has been to clamp the tire in a steam jacketed mold of the type disclosed, wherein the 4heat applied serves to vulcanize suitable materials supplied therein, and form a new tread upon said tire, or repair such portion of the tire as may be` desired. InA clamping the tire, within the mold it was` formerly the prac- 'f ironor other rigid Specification of Letters Patent.

Patented Sept. 21 i920.

Application filed March 30, 1920. Serial No. 370,288.

material within that portion of the tire to be vulcanized, against which clamps were caused to 4eii'ert the desired pressure.

Variations in lthickness of the core, the

tire, the vulcanizing materials, or the mold prevent an even and equal distribution of pressure when a rigid core of this character is used. In the present practice a core formed of a canvas casing filled with sand is frequently substituted for the rigid core of iron. A pad of this character rarely lasts for more' than three or four operations, and a bunching of the sand within the canvas often prevents equal distribution of pressure. My invention provides a core, or vulcanizing pad of a character adapted to overcome the objectional features of the types of pad now in use.

Referring to the drawings the @numeral 1 is used to designate in general a `mo1d provided with a steam chamber 2f adapted to heat a concave retreading surface 3, 'of approximately the curvature of a tire 4 to be vulcanized therein. "Within the tire 4 and bearing against that portion of said tire which is in contact with the heating surface 3, is applied a vulcanizing pad 5 comprising a casing 6 formed of an inner layer.

7 of a suitable flexible material, an interme diate layer 8 of, fabric oi other suitable binding material of a pliable nature, and an outer layer 9 of a suitable heat insulating material such as asbestos, said casing 6 being filled with a granular fil ing 10, preferably sand. The casing 6 is provided at the upi per portion thereof -With a flattened surface ll, serving as bearing surface for'a rigid clamping sti-ip 'l2 against which pressure is applied by suitable clamps 1li. One end of the casing 6 is closed by means of a plug 16 permanentlyvulcanized therein; the other end being closed by a cylindrical plug 17 removably retained therein by friction against the walls o'f the casing 6.

'lhe inner wall 7 of the casing 6 is made preferably of vulcanized rubber, which also serves as a binding material for a plurality of layers of fabric forming the intermediate layer 8 of said casing 6. The outer wall 8 is made preferably of asbestos which adds slightly to the rigidity of the casing and as a heat insulator prt-vents overheating of the rubber, thereby causing said rubber to become hard `or bnittlc. The rubber fabric and asbestos are vulcanized together to form a Wad for the casing'. in this manner an extreruelyD tough casing is formed, adapted to [withstand long and constant usage and at the same time' of a pliability adapted ,to

. readily' conform to the contour of the tire to be vulcanized. llhe construction has the f .l with which the casing is used, thereby preventing friction against the inner Wall of the .tire due to expansion to a greater or lesser degree than said tire When subjected to the heat process. The granular filling lends itself readily to variations in the thickness f thetire with which the pad is used,l and Yight irregularities in any of the bearing A.eurfalzes are taken up and pressure imparted v equally at all points.

.filling Within said casing; and means for .retaining said filling Within the casing.

The flattened surface lilv is adapted to form a stable bearing surface for the pressure from the clamps ll is distributed evenly for the entire length of the, pad and for a .'Widthsuflicient to insure efficient application of pressure upon the entire bearing surface of the pad. facilitates the application of the tire and. the Withdrawal therefrom by providing a diameter smaller than the inner' diameter of the tire. i

Having thus described my invention, what I' claim as new @ters Patent is:

l. A vulcanizing pad comprising a flexiblecasing formed of a layers embedded in a lining of vulcanized rubber, said casing being closed at one end thereof and provided with a flattened pressure receiving surface on the upper portion thereof; a granular iillingi Within said casing; and means for retaining said filling Within thecasing.

2. A vulcanizing pad'cornprising a flexible casingv formed of an inner linino' of vulcanized rubber, an intermediate layer of fabric, and an outer layer of a heat insulating material, said layers being vulcanized to form a Wall forsaid casing; a granular 3. A vulcanizing pad comprising a flexible casingformed of an inner lining of rub-l ber, an intermediate layer of fabric, and an outer layer of asbestos, #said layers being vulcanized to form a Wall for said casing;

The flattened surface also pad to the f and desire to secureI by Let-y plurality of fabric i a granular filling Within sa'dcasing; and means for retaining saidl fillmg Within the casin 4. l vulcanizing pad comprising a flexmeans vfor retaining said filling With the casing. y

5. kA vulcanizing pad comprlsmg a flex- Aible casing vclosed at one end thereof, and

having a attened pressure receiving surface on the upper portion thereof, said casing being formed with an inner lining ofA rubber, an intermediate layer of fabric and an outer layer of asbestos,l said layers being vulcanized'to form a wall for said casing; a granular filling Within said casing; andav plug .engaging the open end of thejcasing for retaining said granular filling Within said casing.

6. A vulcanizing pad comprisingv a'lexible casing closed at one endthereof, and having a flattened pressure receiving sur-v face on the upper portion thereof, said casing being formed with an inner lining of rubber, an intermediate layer of fabric and' an outer layer of asbestos, said layers being 4 vulcanized to form a Wall for said' casing; a granular filling Within said casing; and a plug removably engaging the open end' of the casing for retainingsaid granular filling y within said casing.

7. A vulcanizing pad comprising a flexible casing closed at one end thereof, and

having'l a flattened pressure receivingsur# face on the upper portion thereof, said casing being formed with an inner lining of rubber, an intermediate layer 'of fabric and an outer layer of asbestos, said layers being vulcanized to form a Wall for said casing; a granular lilling Within said casing; and Aa cylindrical plug removably engaging the open end of the casing for retaining said granular' filling Within said casing.

In Witness whereof l' hereunto set my signature.

JULIUS N, DIESER. 

